Modul (%) in python not like in C?

[J. Cliff Dyer]

Dotan Cohen wrote:
> FIrst of all, how is the % symbol (as in 70%6=4) called in English?
>
> Second, in Turbo C -111%10=-1 however in python -111%10=9. Is one or
> the other in error? Is this a known gotcha? I tried to google the
> subject however one cannot google the symbol %. Thanks in advance.
>
> Dotan Cohen
>   

The % operator is called "modulo" in English.  I don't think the 
difference in implementation is an error.  It's just a difference of 
calculation method. 

Python will always yield a number x = m%n such that 0 <= x < n, but 
Turbo C will always yield a number such that if x = m%n -x = -m%n.  That 
is, since 111 % 10 = 1, -111 % 10 = -1.  The two values will always 
differ by n (as used above). 

I'm sure there are mathematicians on the list who can give you a more 
technical, precise explanation of the reasons for the different results.

Cheers,
Cliff